Liquid crystal display module

ABSTRACT

A liquid crystal display module for preventing noise caused by friction between a support main and a light guide plate is provided. In the module, a hole is defined at a support main having at least one of a polygonal shape or a circular shape. A light guide plate is disposed on the support main. A protrusion which protrudes from a side surface of the light guide plate is inserted into the hole. The protrusion has at least one of said polygonal shapes and said circular shape.

This application is a divisional application of U.S. application Ser.No. 10/745,705, filed on Dec. 29, 2003 now U.S. Pat. No. 7,139,047,which claims the benefit of Korean Patent Application No. P2003-39639,filed on Jun. 19, 2003, which are hereby incorporated by reference forall purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a liquid crystal display module, and moreparticularly to a liquid crystal display module that prevents physicalnoise caused by friction between a support main and a light guide plate.

2. Description of the Related Art

Generally, a liquid crystal display (LCD) includes a liquid crystaldisplay module, driving circuitry for driving the liquid crystal displaymodule, and a case.

The liquid crystal display module consists of a liquid crystal displaypanel having liquid crystal cells arranged in a matrix between two glasssubstrates, and a backlight unit which irradiates light onto the liquidcrystal display panel. The liquid crystal display module is arrangedwith optical sheets which vertically raise light traveling from thebacklight unit toward the liquid crystal display panel.

However, the aforementioned liquid crystal display panel, backlight unitand optical sheets must engage with each other in an integral shape toprevent light loss and have protection from a damage caused by anexternal impact. Thus, a case for the LCD enclosing the back light unitand the optical sheets including the edge of the liquid crystal displaypanel is provided. The above-mentioned LCD is mounted in a portableinformation processing device such as a notebook personal computer tothereby be used as a display device.

Referring to FIG. 1 and FIG. 2, a related art liquid crystal displaymodule includes a support main 14, a backlight unit and a liquid crystaldisplay panel 6 disposed at an inside of the support main 14, and a casetop 2 for securing the liquid crystal display panel 6 and the supportmain 14.

The liquid crystal display panel 6 comprises an upper glass substrate 6a and a lower glass substrate 6 b. Liquid crystal cells are arranged inan active matrix type between the upper glass substrate 6 a and thelower glass substrate 6 b, and are provided with thin film transistorswhich switch video signals. The liquid crystal display panel 6 changes arefractive index of each liquid crystal cell in accordance with videosignals thereby displaying a picture corresponding to the video signals.An upper polarizing sheet 4 a is attached to an upper side of the upperglass substrate 6 a while a lower polarizing sheet 4 b is attached to arear side of the lower glass substrate 6 b.

A tape carrier package (not shown) mounted with a driver integratedcircuit that applies a driving signal to the thin film transistor isattached to the lower substrate 6 b of the liquid crystal display panel6.

The support main 14 is molded and an inner side wall surface thereof ismolded into a step coverage face. The step coverage face of the supportmain 14 is mounted with a back light unit and the liquid crystal displaypanel 6 is disposed thereon.

The backlight unit includes a lamp 21, a lamp housing 23, a reflectivesheet 12, a light guide plate 10 and optical sheets 8.

The lamp 21 includes a cold cathode fluorescent lamp. A light generatedfrom the lamp 21 is incident, via an incidence face at the side of thelight guide plate 10, to the light guide plate 10.

The lamp housing 23 has a reflective face at its inner side whichreflects light from the lamp 21 into the incidence face of the lightguide plate 10.

The reflective sheet 12 is positioned at a rear side of the light guideplate 10 to re-reflect an incident light, via the rear side of the lightguide plate 10, to the light guide plate 10, thereby reducing lightloss.

An incidence face of light guide plate 10 engages with the lamp housing23, and a second portion of the light guide plate 10 secures to thesupport main 14. The light guide plate 10 converts a line light inputfrom the lamp 21 into a plane light thereby guiding the light into theliquid crystal display panel 6. Simultaneously, the reflective sheet 12reflects light traveling into the lower side of the light guide plate 10toward the liquid crystal display panel 6. A light output from the lightguide plate 10 with the lamp 21 is incident, via a plurality of opticalsheets 8, to the liquid crystal display panel 6.

The optical sheets 8 allow light input from the light guide plate 10 totravel vertically into the liquid crystal display panel 6. To furtherillustrate, the optical sheets 8 change a light path perpendicularly tothe liquid crystal display panel 6. The optical sheets 8 comprise firstand second prism sheets between first and second diffusing sheets.

The case top 2 has a square band shape including a plane part bentperpendicularly and a side part bent perpendicularly. The top case 2encloses an edge of the liquid crystal display panel 6 and the supportmain 14.

Upon assembling the liquid crystal display module, the support main 14and the light guide plate 10 are provided with a plurality of engagingparts 50 for engagement between the support main 14 and the light guideplate 10 as shown in FIG. 3.

More specifically, each engaging part 50 comprises a square hole 20 at aside of the support main 14, and a protrusion 25 protruding from a sideof the light guide plate 10. The protrusion 25 at the light guide plate10 protrudes, by a desired length, from each side surface and a lowersurface of the light guide plate 10 as shown in FIG. 4. Each square holeat the support main 14 is formed a certain size at a portioncorresponding to the protrusion 25 provided at the light guide plate 10as shown in FIG. 4 such that the protrusion 25 can be inserted into eachsquare hole.

As described above, in a related art liquid crystal display module, theprotrusion 25 of the light guide plate 10 is inserted into the squarehole 20 of the support main 14 thereby securing the light guide plate 10to the support main 14. As shown in FIG. 5, each corner of the lightguide plate 10 is opposed to each corner 30 of the square hole 20 of thesupport main 14 in a diagonal direction. The support main 14 is formedfrom a relatively lightweight mold product which reduces a weight of theliquid crystal display module. Thus, if an external force is applied toone side of the related art liquid crystal display module, twist occursat the liquid crystal display module. In addition, the support main 14twists into one side thereof by an external force applied to one side ofthe support main 14 as shown in FIG. 6. Accordingly, friction occursbetween the square hole 20 of the twisted support main 14 and the lightguide plate 10, thereby causing noise. More specifically, when thesupport main 14 twists, a lower surface of the square hole 20 contacts acorner portion 38 of an upper side of the light guide plate 10. Thefriction generates noise at the corner portion 38 where the support main14 contacts the light guide plate 10.

Furthermore, in a related art liquid crystal display module, frictionbetween the square hole 20 of the support main 14 and the protrusion 25of the light guide plate 25 caused by twisting of the support main 14generates an alien substance. If the alien substance lodges between thelight guide plate 10 and the optical sheets 8, light passing through thelight guide plate 10 may shut off thereby causing a black spot at aposition of the liquid crystal display panel 6 corresponding to thealien substance.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to liquid crystal displaymodule that substantially obviates one or more of the problems due tolimitations and disadvantages of the related art.

Accordingly, it is an advantage of the present invention to provide aliquid crystal display module that prevents friction between the supportmain and the light guide plate. Additional features and advantages ofthe invention will be set forth in the description which follows, and inpart will be apparent from the description, or may be learned bypractice of the invention. The objectives and other advantages of theinvention will be realized and attained by the structure particularlypointed out in the written description and claims hereof as well as theappended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, anembodiment of the present invention includes a support main; a holedefined at the support main having at least one of polygonal shapes anda circular shape; a light guide plate disposed on the support main; anda protrusion protruding from the side surface of the light guide platefor insertion into the hole, said protrusion being formed to have atleast one of said polygonal shapes and said circular shape.

In the liquid crystal module, the corner of the protrusion may beinclined.

Alternatively, the corner of the protrusion may be formed to have acircular shape.

Herein, the shortest distance between the protrusion and the hole issubstantially equal to the height of the protrusion.

The center of the hole has a stepped portion.

Alternatively, the center of the hole is formed to have a circularshape.

Otherwise, the corner of the hole is formed to have a circular shape,and the corner of the protrusion is formed to have a circular shape.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is an exploded perspective view showing a structure of a relatedart liquid crystal display module;

FIG. 2 is a cut-away section view of one side of the liquid crystaldisplay module shown in FIG. 1;

FIG. 3 illustrates engaging parts for securing a light guide plate to asupport main of the liquid crystal display module shown in FIG. 1;

FIG. 4 is a plan view of a light guide plate shown in FIG. 2;

FIG. 5 illustrates an A portion at which the support main shown in FIG.1 is engaged with the light guide plate;

FIG. 6 is a sectional view showing twist of the support main shown inFIG. 1;

FIG. 7 is an exploded perspective view showing a structure of a liquidcrystal display module according to a first embodiment of the presentinvention;

FIG. 8 is a cut-away section view of one side of the liquid crystaldisplay module shown in FIG. 7;

FIG. 9 illustrates an engaging part B of a support main shown in FIG. 8with a light guide plate;

FIG. 10 is a sectional view showing twisting of the support main shownin FIG. 7;

FIG. 11 is a sectional view showing an engaging part of a support mainwith a light guide plate in a liquid crystal display module according toa second embodiment;

FIG. 12 is a sectional view showing twisting of the support main shownin FIG. 11;

FIG. 13 is a sectional view showing an engaging part of a support mainwith a light guide plate in a liquid crystal display module according toa third embodiment;

FIG. 14 is a sectional view showing an engaging part of a support mainwith a light guide plate in a liquid crystal display module according toa fourth embodiment; and

FIG. 15 is a sectional view showing an engaging part of a support mainwith a light guide plate in a liquid crystal display module according toa fifth embodiment.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Referring to FIG. 7 and FIG. 8, a liquid crystal display moduleaccording to a first embodiment of the present invention includes asupport main 114, a backlight unit and a liquid crystal display panel106 disposed at an inside of the support main 114, and a case top 102for securing the liquid crystal display panel 106 and the support main114.

The liquid crystal display panel 106 comprises an upper glass substrate106 a and a lower glass substrate 106 b. Liquid crystal cells arearranged in an active matrix between the upper glass substrate 106 a andthe lower glass substrate 106 b, and include thin film transistors whichswitch video signals. The liquid crystal display panel 106 changes arefractive index of each liquid crystal cell in accordance with videosignals thereby displaying a picture corresponding to the video signals.An upper polarizing sheet 104 a is attached to an upper side of theupper glass substrate 106 a while a lower polarizing sheet 104 b isattached to a rear side of the lower glass substrate 106 b.

A tape carrier package (not shown) mounted with a driver integratedcircuit, which applies a driving signal to the thin film transistor, isattached to the lower substrate 106 b of the liquid crystal displaypanel 106.

The support main 114 is molded, and an inner side wall surface thereofis molded into a step coverage face. An inner side of the support main114 is mounted with a backlight unit, and the liquid crystal displaypanel 106 is disposed thereon. Further, a side surface of the supportmain 114 includes a plurality of holes 120 which secure the light guideplate 110. Each hole 120 is formed by removing a portion of a side frameof the support main 114 in a rectangular shape. Furthermore, inaccordance with an embodiment of the present invention, across-sectional configuration of the hole 120 is a parallelogram.

The backlight unit includes a lamp 121, a lamp housing 123, a reflectivesheet 112, a light guide plate 110 and optical sheets 108.

The lamp 21 includes a cold cathode fluorescent lamp. A light generatedfrom the lamp 121 is incident, via an incidence face in a side of thelight guide plate 110, to the light guide plate 110.

The lamp housing 123 has a reflective face at its inner side whichreflects light from the lamp 121 to the incidence face of the lightguide plate 110.

The reflective sheet 112 is positioned at a rear side of the light guideplate 110 to re-reflect an incident light, via the rear side of thelight guide plate 110, to the light guide plate 10, thereby reducinglight loss.

The incidence face of light guide plate 110 engages with the lamphousing 123, and another portion of the incidence face secures to thesupport main 114. The light guide plate 110 converts line light inputfrom the lamp 121 into plane light thereby guiding the light to theliquid crystal display panel 106. Simultaneously, the reflective sheet112 reflects light traveling into a lower side of the light guide plate110 toward the liquid crystal display panel 106. A light output, via thelight guide plate 110 from the lamp 121 is incident, via a plurality ofoptical sheets 108, to the liquid crystal display panel 106.

Further, the light guide plate 110 includes a plurality of protrusions125 inserted into a plurality of holes 120 provided at a side surface ofthe support main 114. The plurality of protrusions 125 engage with theholes 120. Each protrusion 125 extends a length from the side surface ofthe light guide plate 110. Furthermore, a corner portion at an upperside of the protrusion 125 has an incline plane 124. The incline plane124 includes a desired slope, as shown in FIG. 9. Moreover, theprotrusion 125 has a tetrahedron shape, as shown in FIG. 9. The inclineplane 124 prevents friction with the lower surface of the hole 120 ofthe support main 114.

The optical sheets 108 allow vertical progression of light input fromthe light guide plate 110 to the liquid crystal display panel 106. Thus,the optical sheets 108 change a light path perpendicularly to the liquidcrystal display panel 106. The optical sheets 108 comprise first andsecond prism sheets disposed between first and second diffusing sheets.

The case top 102 has a square band shape including a plane partperpendicularly bent and a side part perpendicularly bent. The top case102 encloses an edge of the liquid crystal display panel 106 and thesupport main 114.

As described above, in the first embodiment of the present invention,the protrusion 125 of the light guide plate 110 is inserted into thehole 120 of the support main 114 thereby securing the light guide plate110 to the support main 114. In the liquid crystal display module of thefirst embodiment, the support main 114 is formed from a relativelylightweight mold product, which reduces the weight of the liquid crystaldisplay module. If an external force is applied to one side of theliquid crystal display module, twist may occur at the liquid crystaldisplay module, as illustrated in FIG. 10. The twisting of the liquidcrystal display module causes twisting of the support main 114 into oneside by an external force 135 applied to one side of the support main114. When the support main 114 twists, the incline plane 124 of theprotrusion 125 of the light guide plate 110 minimizes friction betweenthe hole 120 of the support main 114, which twists from the externalforce 135 and the protrusion 125 of the light guide plate 110.

More specifically, when the external force 135 shakes or twists thesupport main 114, a lower surface of the hole 120 slides by the inclineplane 124 of the protrusion 125. As such, the incline plane 124 of theprotrusion 125 slidably guides the lower surface of the hole 120 of thesupport main 114, thereby preventing noise caused by friction betweenthe hole 120 of the support main 114 and the protrusion 125 of the lightguide plate 110.

In accordance with this embodiment of the present invention, each cornerof the upper side of the protrusion 125 has the incline plane 124. Theincline plane 124 reduces friction between the hole 120 of the supportmain 114 and the protrusion 125 of the light guide plate 110, therebyminimizing noise. Furthermore, the liquid crystal display moduleaccording to the first embodiment of the present invention prevents thegeneration of alien substances caused by friction between the hole 120of the support main 114 and the protrusion 125 of the light guide plate110. As such, this embodiment of the present invention prevents picturequality deterioration of the liquid crystal display panel 106 from aliensubstances.

Referring to FIG. 11, a liquid crystal display module according to asecond embodiment of the present invention includes elements similar tothose described with reference to the first embodiment of the presentinvention except for the protrusion 125 provided at the light guideplate 110. Thus, reference may be made to the first embodiment regardingelements in the second embodiment similar to those described withregards to the first embodiment. Moreover, discussion regarding thesecond embodiment of the present invention will include the protrusion125 at the light guide plate 110.

The protrusion 125 at the light guide plate 110 of the liquid crystaldisplay module according to the second embodiment of the presentinvention protrudes in a square shape at a desired length. Furthermore,each corner of an upper side opposed to the liquid crystal display panelhas a curved face 124. Thus, in the liquid crystal display moduleaccording to the second embodiment, the curved face 124 provides a spacebetween each corner of the hole 120 and each corner of the protrusion125 of the light guide plate 110. The space between the corners of thehole 120 and the corners of the protrusion 125 prevents friction betweenthe hole 120 and the protrusion 125. In this embodiment, as a radius ofthe curve face 124 of the protrusion increases, noise caused by frictionwith the support main 114 reduces. Herein, in an embodiment where athickness of the protrusion 125 is in a range between about 0.6 mm andabout 1.3 mm, a radius of the curved face 124 may equal the thickness ofthe protrusion 125 or may be more than about 0.6 mm.

Accordingly, the liquid crystal display module according to the secondembodiment of the present invention provides each corner of the upperside of the protrusion 125 protruding from the light guide plate 110with the curved face 124. The curved face 124 reduces friction betweenthe hole 120 of the support main 114 and the protrusion 125 of the lightguide plate 110, thereby preventing noise. Furthermore, the liquidcrystal display module according to the second embodiment of the presentinvention prevents the generation of alien substances caused by frictionbetween the hole 120 of the support main 114 and the protrusion 125 ofthe light guide plate 110. As such, this embodiment of the presentinvention prevents picture quality deterioration of the liquid crystaldisplay panel 106.

Alternatively, referring to FIG. 13 and FIG. 14, a liquid crystaldisplay module according to a third embodiment of the present inventionhas elements similar to those previously discussed with reference to theliquid crystal display module according to the first embodiment of thepresent invention. Thus, explanation regarding the elements similar tothose of the first embodiment of the present invention will be omitted.Instead, reference may be made to the discussion above regarding theseelements.

The support main 114 of the liquid crystal display module according tothe third embodiment of the present invention includes a plurality ofholes 120, and a stepped portion 140 having a trapezoidal shaped sectionprotruding from a center of each hole 120.

Each hole 120 is formed by removing a side frame of the support main 114in a square shape. The stepped portion 140 protrudes from each hole 120and opposes an upper surface of the protrusion 125 of the light guideplate 110 inserted into each hole 120.

The stepped portion 140 provided at the hole 120 of the support main 114prevents friction between the hole 120 of the support main 114 and theprotrusion 125 of the light guide plate 110 when the support main 114twists from an external force.

More specifically, when the support main 114 twists or shakes from anexternal force, the stepped portion 140 at the hole 120 contacts theupper surface of the protrusion 125 provided at the light guide plate110, thereby preventing friction between the hole 120 of the supportmain 114 and each corner of the upper side of the protrusion 125 of thelight guide plate 110.

In the liquid crystal display module according to the third embodimentof the present invention, the stepped portion 140 of the hole 120 of thesupport main 114 prevents friction between the hole 120 of the supportmain 114 and the protrusion 125 of the light guide plate 110, therebypreventing noise. Furthermore, the liquid crystal display moduleaccording to the third embodiment of the present invention prevents thegeneration of alien substances caused by friction between the hole 120of the support main 114 and the protrusion 125 of the light guide plate110. Thus, the third embodiment of the present invention preventspicture quality deterioration in the liquid crystal display panel 106.

Alternatively, the stepped portion 140 at each hole 120 of the supportmain 114 may have a circular shaped section as shown in FIG. 14. Thecircular-shaped stepped portion 140 at the hole 120 of the support main114 prevents friction between the hole 120 of the support main 114 andthe protrusion 125 of the light guide plate 110 when the support main114 is twisted by an external force.

Referring to FIG. 15, a liquid crystal display module according to afourth embodiment of the present invention includes elements similar tothe liquid crystal display module according to the first embodiment ofthe present invention. Therefore, an explanation with respect toelements similar to those discussed with reference to the firstembodiment will be omitted.

The support main 114 of the liquid crystal display module according tothe fourth embodiment of the present invention includes a plurality ofholes 220 defined at the side surface of the support main 114. In thisembodiment of the present invention, a configuration of a cross-sectionof the hole 220 has a semi-spherical shape. Each hole 220 is formed byremoving the side frame of the support main 114 in a square shape andforming a rounding 250 of each upper corner of the square shape to adesired length.

The light guide plate 110 includes a plurality of protrusions 225protruding in a semi-sphere shape such that the protrusions may beinserted into each of the holes 220 of the support main 114. Eachsemi-spherical protrusion 225 protrudes from the side surface of thelight guide plate 110. Each protrusion 225 also has a square section anda rounding 224 at each upper corner opposed to the liquid crystaldisplay panel. Each semi-spherical protrusion 225 is inserted into eachhole 220 of the support main 114. The rounding at each upper corner ofthe semi-spherical protrusion 225 is spaced from each corner of the hole220 of the support main 114 at a desired distance.

Accordingly, the liquid crystal display panel according to the fourthembodiment of the present invention has the hole 220 of the support mainand the semi-spherical protrusion 225 provided at the light guide plate110. Thus, the fourth embodiment of the present invention preventsfriction between the hole 220 of the support main 114 and thesemi-spherical protrusion 225 of the light guide plate 110 when anexternal force twists the support main 114.

More specifically, when an external force twists or shakes the supportmain 114, the hole 220 of the support main 114 contacts the curve faceof the semi-spherical protrusion 225 provided at the light guide plate110. When the hole 220 contacts the curve face of the semi-sphericalprotrusion 225, the hole 220 slides.

Accordingly, the liquid crystal display module according to the fourthembodiment of the present invention provides the support main 114 withthe hole 220 and provides the light guide plate 110 with thesemi-spherical protrusion 225 thereby preventing friction between thesupport main 114 and the light guide plate 110, and, as a result, noise.Furthermore, the liquid crystal display module according to the fourthembodiment of the present invention prevents the generation of aliensubstances caused by friction between the support main 114 and the lightguide plate 110 thereby preventing picture quality deterioration in theliquid crystal display panel 106.

As described above, the liquid crystal display module according to thepresent invention provides a variety of configurations for a shape of aprotrusion of a light guide plate inserted into a hole of a supportmain. The configurations secure a light guide plate to a support main,thereby preventing noise caused by friction between the support main andthe light guide plate during twisting or shaking of the liquid crystaldisplay module. Furthermore, the present invention prevents generationof alien substances caused by a friction between the support main andthe light guide plate.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A liquid crystal display module, comprising: a support main mountedwith the liquid crystal display module; a hole formed by removing aportion of a side frame of the support main, the hole having a polygonalshape; a light guide plate disposed on the support main; and aprotrusion protruding from the light guide plate and having a circularshape wherein the protrusion is disposed within the hole.
 2. The liquidcrystal display module according to claim 1, wherein a corner of theprotrusion has a circular shape.
 3. The liquid crystal display moduleaccording to claim 2, wherein a shortest distance between the protrusionand the hole is substantially equal to a height of the protrusion.
 4. Aliquid crystal display module, comprising: a support main mounted withthe liquid crystal display module; a hole disposed within the supportmain, the hole having a polygon shape; and a light guide plate disposedwithin the support main, the light guide plate having a protrusion, theprotrusion having a curved face wherein the protrusion is disposedwithin the support main hole.